Tamper-proof envelope



July 1-4, 1970 z. KUKULSKI 3,520,472

TAMPER-PROOF ENVELOPE Filed July 5. 1968 2 Sheets-Sheet l PLMWA/WVVWWINVENTOR. ZDZISLAW KUKULSKI ATT ORN EY Z. KUKULSKI TAMPER July 14, 1970-PROOF ENVELOPE 2 Sheets-Sheet 2 Filed July 5. 1968 FIG 2 INVENTOR.

ZDZISLAW KUKULS K ATTO RNE United States Patent O M 3,520,472TAMPER-PROOF ENVELOPE Zdzislaw Kukulski, 2101 Bridgeway, Sausalito,Calif. 94965 Filed July 5, 1968, Ser. No. 742,664 Int. Cl. B65d 27/30U.S. Cl. 229-80 7 Claims ABSTRACT F THE DISCLOSURE Envelope oftransparent plastic, with opacifying liner divided in two parts by azig-zag heat seal, and having flaps at both ends with adhesive protectedby release sheet, the envelope when folded, adapted to make a tight fitin a further envelope for mailing, the construction being proof againsttampering Without leaving evidence of such.

This invention relates to a waterand tamper-proof mailing envelope orcontainer.

An objectiof the present invention is to provide a mailing envelope orcontainer that will withstand the destructive effects of climateextremes, such as excessive heat and humidity as encountered in tropicalareas, dust penetration, tarnish of fading and protection from insectattack. Further the construction is such as to eliminate the chance oftampering without leaving visible evidence thereof, and to furthereliminate the possibility of inspection of the contents Without breakingthe seal as by strong light or other means.

The above and other novel features of the invention will appear morefully hereinafter from the following detailed description when taken inconjunction with the accompanying drawings. It is expressly understoodthat the drawings are employed for purposes of illustration only and arenot designed as a definition of the limits of the invention, referencebeing had for this purpose to the appended claims.

In the drawings, wherein like reference characters indicate like parts:

FIG. 1 is a plan view of the container before sealing;

FIG. 2 is a plan view of the container sealed and folded;

FIG. 3 is a plan view of one end of the container before sealing, andbefore applying the signature tag; and

FIG. 4 is a plan view of a modified container.

Referring to the drawings, there is shown a container comprising a bodyportion in flat form and of seamless tubular plastic such as thin Mylaror the like. The tubular portion which is flat and extends from the flapfold line 22 at one end to the flap fold line 24 at the other end. Thetubular sleeve may have a width slightly less than the length of anenvelope into which it may be inserted, and a length between fold lines22 and 24 of nearly double the Width of the envelope for which it isdesigned. The tubular sleeve will be partially heat sealed preferablyalong a zig-zag line across the center as indicated at 25, to form twopockets 26 and 28, the seal securing the two walls together sufficientlyto prevent separation without a degree of destructive effect to one orthe other or both walls of the sleeve.

One wall of the sleeve is extended at each end to form flaps 30 and 32.For economy one wall may be extended at one end and the other wallextended at the other, for this purpose. The flaps are clear transparentplastic. The internal wall of the body portion is rendered opaque by theapplication of black paint, or a metallized surface such as to renderthe sleeve portion impenetrable by strongly concentrated light, and thusprevent observation of the contents. Such internal metallized or opaquesur- 3,520,472 Patented July 14, 1970 ICC faces in combination with theclear plastic tends to intercept and reflect light directed at thecontainer and thus prevent any observation of the contents therewithin.

Within the areas indicated by the broken lines 40 and 42 which outlinethe area over which the respective flaps will extend when sealed, is asignature tag 44 or label of thin paper adhesively attached to the sideWall of the sleeve. Such tag or label will be of material susceptible ofbeing written on with ink or pencil, and the area thereof willpreferably be such as to be completely covered by the flap andsurrounded by adhesive 46 so that when the flap is folded over, the tagwhile visible through the transparent flap is completely enclosed by thesealing effect of the adhesive employed on the sleeve wall, as Well asthe flap as at 48 and50.

In practice the adhesive will be such that when the flap is once foldedover the sleeve wall and the adhesive placed under pressure, the flapand sleeve wall take on a bonding effect such that the flap may not beseparated from the sleeve wall Without destruction of the pocket wall orthe furnishing of evidence of the tampering.

The adhesive surfaces of the flap and sleeve side wall may be protectedprior to use by silicone treated release sheets of plastic or papermaterial which will adhere lightly to the adhesive coated surfaces butwhich may be readily removed to expose the adhesive immediately prior tosealing over the flaps to seal the pockets. Such sheets are shown inposition at one end as at 60 and 62 with pull tabs 61 and 63.

It will be seen that the seal dividing the pockets protects one of thepockets from access from the other without evidence thereof, should theother pocket be tampered with. The container when folded at themidsection along the center of the zig-zag partial heat seal, and withboth aps sealed, is readily slipped into a mailing envelope havingdimensions just a little larger, so as to neatly receive the container.A letter comprising two or more sheets may have one or more sheetssealed into one pocket and remaining sheets sealed into the other.

In the modified form shown in FIG. 4, the adhesive for each flap isapplied in strip form to the flap as at 70 and to the sleeve wall as at72, and such adhesive protected until ready for use by silicone or waxtreated release sheets 74 and 76. By such arrangement the adhesive onthe ap and that on the sleeve exterior are complemental when the flap isfolded for sealing, and protected by the release sheets until it is timefor use.

In general, the folded tubular portion will be made so as to fit withina standard size envelope. In inserting mail into a pocket, the releasesheet may be removed from the sleeve, to expose the tag, and whileprotecting the flap adhesive while inserting the correspondence into thecontainer. Thereafter the release sheet is removed completely, and theflap sealed. By employing thin signature tag paper 44, removal from itsadhesion to the plastic sleeve may be prevented without tell-taledamage. The use of the zig-zag heat seal tends to prevent cutting theseal away from the plastic and resealing, without materially andnoticably varying the size so as to render obvious the effect of suchtampering. If desired a single container may be provided with a singleflap, and a zigzag seam.

While several modifications of the invention have been illustrated anddescribed, it is to be understood that the invention is not limitedthereto. Various changes in the construction and arrangement may be madewithout departing from the spirit of the invention, as will be apparentto those skilled in the art.

What is claimed is:

1. A tamper-proof letter mailing container, adapted to fit in anenvelope, comprising a tubular section of thin wall transparent plastic,the inside wall of which is coated with Opacifying medium to reflectlight.

2. A container as set forth in claim 1, wherein the tubular section isin the form of a seamless flat sleeve, and in which one side of thesleeve has an integral flap extension for folding over the end of thesleeve, and an adhesive ap sealant applied to the container.

3. A container as set forth in claim 1, wherein one end of the tubularsection is heat sealed along a zig-zag line to prevent access Withoutinjury to a considerable portion of the end of the section.

4. A container as set forth in claim 2 wherein the sleeve is heat sealedalong a zig-zag line at one end.

5. A container as set forth in claim 1 wherein the tubular section is inthe form of a at sleeve, having a flap extension at each end and inwhich the sleeve is divided centrally 'by a zig-zag heat seal, and inwhich a sealant is applied to the container for each of the flaps.

6. A container as set forth in claim 5 `wherein the adhesive is coveredwith a release sheet.

4 7. A container as set forth in claim 5 wherein an identification tagis adhesively monded to the outside wall of one side of the sleeve andwithin the area covered by a closed flap.

References Cited UNITED STATES PATENTS 942,420 12/ 1909 Swett. 1,800,1434/ 1931 Hughes 229-48 2,756,875 7/1956 Yochim 229-72 X 3,120,336 2/1964Whatley 229-66 3,439,868 4/1969 Kuhnle 229-74 FOREIGN PATENTS 24,710 8/1901 Switzerland.

DAVID M. BOCKENEK, Primary Examiner U.S. Cl. X.R.

